of Lombards who were Vulgar Latin variety-speaking and more inclined to support the Western church. With time, Sicily would become overwhelmingly Roman Catholic and a new vulgar Latin idiom would emerge that was distinct to the island. Palermo continued on as the capital under the Hauteville. Roger's son, Roger II of Sicily, was ultimately able to raise the status of the island, along with his holds of Malta and Southern Italy to a kingdom in 1130. During this period, the Kingdom of Sicily was prosperous and politically powerful, becoming one of the wealthiest states in all of Europe; even wealthier than England. The Siculo-Norman kings relied mostly on the local Sicilian population for the more important government and administrative positions. For the most part, initially Greek, Arabic and Latin were used as languages of administration while Norman was the language of the royal court. Significantly, immigrants from France, England, North Europe, Northern Italy and Campania arrived during this period and linguistically the island would eventually become Latinised, in terms of church it would become completely Roman Catholic, previously under the Byzantines it had been more Eastern Christian. Roger II's grandson, William II (also known as William the Good) reigned from 1166 to 1189. His greatest legacy was the building of the Cathedral of Monreale, perhaps the best surviving example of Siculo-Norman architecture. In 1177, he married Joan of England (also known as Joanna). She was the daughter of Henry II of England and the sister of Richard the Lion Heart. When William died in 1189 without an heir, this effectively signalled the end of the Hauteville succession. Some years earlier, Roger II's daughter, Constance of Sicily (William II's aunt) had been married off to Henry who was son of Emperor Frederick I and would later become Emperor Henry VI, meaning that the crown now legitimately transferred to him. Such an eventuality was unacceptable to the local barons, and they voted in Tancred of Sicily, an illegitimate grandson of Roger II. During his reign Tancred was able to put down rebellions, defeat an invasion by Henry VI and capture Empress Constance, but Pope Celestine III forced him to release her. Hohenstaufen reign (1194–1266) Tancred died in 1194, just as Henry VI and Constance were travelling down the Italian peninsula to claim their crown. Henry rode into Palermo at the head of a large army unopposed and thus ended the Siculo-Norman Hauteville